Drill-steel retainer



G. G. TUTTLE.

DRILL STEEL RETAINER.

APPLICATION man JUNE 2.1921.

PatentedSept. 19, 1922.

INVENTOR @www @Z5/iff@ Patented Sept. i9, i922.

GROVER G. TUTTLE, OF PHILLIPSBURG, NEW JERSEY, ASSIGNOR T0INGERSOLL-RAND COMPANY, OF JERSEY CITY, NEW JERSEY. A CORPORATION OF NEWJERSEY.

DRILL-STEEL RETAINER.

Application filed June 2, 1921.

To all lwhom t may concern.'

Be it known that I, GRovnR G. TUTTLE, a citizen of the United States, aresident of Phillipsburg, county of l/Varren, State of New Jersey, haveinvented a certain Drill- Steelvletainer, of which the following is aspecification accompanied by drawings.

This invention relates to drill steel retainers for rock drills, butmore particularly to that type of retainer in which a yoke embraces thedrill steel and is suitably held or clamped in position upon the fronthead of the machine.

Such yoke retainers are subjected to severe impact as the collar on thedrill steel strikes the yoke and various devices have been employed tocushion or yieldingly hold the yoke to avoid breakage of the parts, someof these devices including bolts and springs, but the breakage isdiiicult to overcome, and the more complex the parts, the greater thedanger of breakage becomes.

The primary objects of the present invention are to simplify theretainer construction, and reduce the chances of breakage by avoidingthe use of retainer bolts and supporting the yoke retainer from thefront head of the machine by means of an arrangement of main andsupplementary springs which cushion the yoke in both directions.

Another object of the invention is to supplement the expansive force ofthe main springs in holding the retainer, by means of fluid underpressure, which may be the live pressure taken from the supply inlet ofthe machine. In such case, if the pressure fails for any reason, themain retainer springs still fulll the function of exerting pressure tocushion the yoke. Another object of the invention is to make the casingsfor the springs separate from the front head and mount them to swingrelatively to the front head, carrying the yoke retainer with them. Thisavoids the necessity of pivoting the yoke retainer to the spring casingsand permits a simple connection between the retainer and the springcasings.

To these ends the invention is shown in its preferred forms in theaccompanying drawings, in which- Figure 1 is a diagrammatic frontelevation of the front head of a rock drill having my drill steelretainer applied thereto, parts Serial No. 474,479.

of the front head and retainer being shown in vertical section,

igure 2 is a side elevation of the device, an

Figure 3 is a horizontal sectional plan view of Figure l on the line 33.

Referring to the drawings, A represents diagrammatically the front headof a rock drill having the nose piece B, adapted to receive the usualfront head bushing C, through which the drill steel D having the collarE, is adapted to extend in position to receive the impact blows of thehammer. The front head is provided with the usual lugs F through whichthe side bolts G eX tend for clamping the cylinder and front headtogether. In this instance the front end portion H of the cylindercasing is shown dinagrammatically and partly broken away to indicate therelation of the parts.

ln accordance with my invention the front head is provided with cushionholding guides J pivoted at opposite sides of the machine and maincushioning means in the form of coiled springs K are guided and heldwithin said `guides J. In order to suitably pivot the guides J so thatthey may swing at each side of the front head, the said front head isconveniently provided with trunnions L` and the guides J are formed withbosses or bearing portions O forming sockets for `the trunnions L. Forpurposes hereinafter to appear, leather washers` P are .preferablyarranged between the socket portions ofthe guides and the front head andunderneath the caps Q which are secured to the trunnions as by means ofthe screws R thus forming air tight joints around the trunnions. Springpressed pins or detents S in the trunnions are adapted to cooperate withthe notches T in the socket pieces for centering and maintaining theguides in longitudinal position except when moved out of said position.

A yoke retainer U for the drill steel is provided with arms V guided inthe spring holding guides J and slidable longitudinally in said guides.The shanks or arms V of the yoke extend through. the necks WV of theguides and cup leathers or washers of any suitable material X are seatedover the yoke arms in the bottoms of the recessed portions Y of theguides. The. main springs K, preferably coiled springs, surround theyoke arms vious that'the yoke retainer may be swung and caps Z arepreferably placed over the springs to act as bearings. Cup leathers a orwashers of any suitable material are placed over the caps Z and nuts bover the washers c are secured to the ends of the bolts and retained inposition as by means of suitable cotter pins (Z. Supplementary springse, preferably coiled springs, are arranged within the guides J over theshanks V and between the nuts b and bearing intoand out of retainingposition about the trunnions L, in whichcase the entirespring guides andyoke pivot about the trunnins. When the'yoke is in retaining positionthe -1 main springs K resist the blows of the collar E vof the drillsteelagainst the yoke and the supplemental springs e resist pressure inthe opposite direction and serve. to retract the yoke.

`The packing in the form of washers l) and cup leathers X and aeffectivelyvseal the chambers formed within the recessed portions oftheA guides J so that `the air pressure, preferably live air, admittedto said chambers tends to assist the expansive force of' the mainspringsA K, although if these springs are made suiliciently strongthey-will accomplish their purpose without the assistance ot thecompressed air. The

l air, however, is a valuable adjunct in a de- A`rice of this character.

I claim: l. A drill steel retainer for rock drills, comprising cushionholding guides pivoted machine, coiled springs held within said guides,a yoke retainerfor the drill steel having arms guided in said guides andcushioned by said springs, and means for maintaining fluid pressurewithin said guides to supplement the expansive torce of the cushioningmeans in one direction.

3. A drill steel retainer for rock drills, comprising spring holdingguides pivoted atopposite sides of the front head of the machine, coiledsprings held within said guides, a yoke retainer' for the drill steelhaving arms slidable longitudinally in said guides and cushioned in bothdirections by said springs, and means for maintaining fluid pressurewithin said guides to supplement the expansive force ol the cushioningmeans in one direction. l

A drill-steel lretainer for rock drills, comprising spring holdingguides pivoted at opposite sides of the front head of the machine, mainand supplementary springs wholly within said guides, a yoke retainer forthe drill stee-l having arms slidable in said guides and cushioned inboth directions by said main and supplementary springs respectively, andmeans for maintaining fluid pressure within said guides to supplementthe expansive force of the cushioning means in one direction.

yIn testimony whereofv lA have signed this specilication. GROVER G.TUTTLE.

